We regularly perform expert CRO reviews of web designs for our clients. What informs these reviews? Is it just our aesthetic opinion? Must a design look a certain way to be effective at conversions? No. But whatever their appearance, conversion-optimized designs do share some common traits, and in this article I’ll discuss three I consider to be fundamental.

Trait #1: It’s Usable

Usability is the underlying framework for every conversion-optimized design. Think of it this way: if a web site were a house, usability would be the building code requirements that make structures work for human beings; doors must be so wide, ceilings so high, light switches wired in such a way that they don’t electrocute you when you visit the bathroom at night. It might not be glamorous or edgy, but usability makes things safe, easy, and efficient for users.

Since usability is so foundational, its fundamentals underlie much of what I look for during a CRO review. Take, for example, the basic usability concept of “affordance.”